1. Technical Field
The present disclosure relates to lamp sockets, and in particular, to a lamp socket adapted to ensure that a lamp is fully engaged prior to being energized.
2. Description of Related Art
Fluorescent lamps typically comprise a hermetically scaled structure or tube containing one or more eases with a small amount of mercury contained therein. The tube is typically coated with a phosphor-based power along the inside of the tube. Additionally, fluorescent lamps also generally contain two electrodes spaced apart and configured such that current flows through the gas and mercury under certain conditions. When sufficient electric charge is applied between the electrodes, electrons migrate through the gas away from one electrode and towards the other. As aggregate electric charge is displaced, some of the electrons collide with the vapor-phase mercury and excite the electrons contained therein into higher energy states (sometimes incorrectly referred to as “orbital” states). Quickly thereafter, these excited vapor-phase mercury atoms (ionized mercury gas) quickly drop to a lower excitation state and release one or more photons equal to the energy loss resulting from the reduced excitation state of the gas-phase mercury atom. The photons released from the mercury gas are mostly in the ultraviolet region of the light spectrum, and consequentially, are invisible to the human eye and are not typically desirable for human lighting. However, the phosphor-based coatings on the inner surface of the lamp absorbs these UV photons. The absorption of the UV photons excites the phosphor atoms, which alter rising to a higher energy state, quickly return to a lower energy state giving off light mostly in the visible spectrum. These fluorescent lamps typically include at least one pin and commonly two pins electrically connected to an electrode. Each electrode is at the end of the hermetically sealed tube.
In some configurations, current is injected between the two pins of the electrode to heat the electrodes to “boil off” electrons from the metal surface sending them into the gas to partially ionize the gas. However, in some embodiments, this function is bypassed and the two pins are simply electrically connected together in the control circuitry, the lamp socket and/or in the lamp housing. These fluorescent lamps have a life span and therefore need frequent replacing from time to time. Several fluorescent lamp designs have been standardized including their respective lamp sockets; for example, T5, T8 and T12 are standard fluorescent lamp designs and have standardized socket requirements. Lamp sockets are designed so that fluorescent lamps may be quickly installed and/or removed. Typically, the lamp sockets are installed by a technician that inserts the pins of the fluorescent lamp into a socket (usually from the side) and rotates the lamp to secure the lamp within the lamp fixture. These fluorescent lamps are usually electrically connected immediately upon insertion or after a minimal amount of rotation. When a fluorescent lamp is inserted into a lamp socket and not fully rotated, the lamp holder may not be fully seated which may be undesirable.
As such, it would be desirable to configure a lamp socket to ensure that the lamp is fully engaged prior to the lamp being energized. One such configuration is disclosed in commonly owned U.S. patent application Ser. No. 12/243,509, which was tiled on Oct. 1, 2008 to Gregory Gallecio et al., entitled “LAMP SOCKET HAVING A ROTOR ASSEMBLY,” the entirety of which is incorporated herein by reference. As provided therein, the lamp socket preferably included a housing, a rotor and a pair of electrical contacts disposed within the housing. The housing preferably included a notch while the rotor preferably included a channel, the notch and channel were adapted and configured to receive the lamp pins extending from the fluorescent lamps.
In use, the rotor was rotatably received within the housing between first and second positions. In the first position, the channel formed in the rotor was aligned with the notch formed in the housing so that the lamp pins could be received through the notch of the housing and into the channel of the rotor. Additionally, the electrical contacts were operatively and electrically disengaged from the lamp pins. Once the lamp pins were inserted into the channel formed in the rotor, the lamp and hence the rotor could be rotated to the second position, which was at a predefined radial angle from the first position (preferably 90 degrees). In the second position, the channel formed in the rotor was not aligned with the notch formed in the housing so that the lamp pins and hence the lamp were secured to the socket assembly. Additionally, the electrical contacts operatively and electrically engaged the lamp pins. In this design, the rotor included a series of protrusions that would radially push the electrical contacts outward, away from the lamp pins until the rotor was in the second position, in which case, the rotor was configured to permit the electrical contacts to protrude into the channel and into engagement with the lamps pins.
It is therefore desirable to provide a design for preventing the electrical contacts from contacting the lamp pins until the lamp is fully secured to the lamp socket.